/*******************************************************************************
 * Copyright (c) 2009 Luaj.org. All rights reserved.
 * <p/>
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * <p/>
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * <p/>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/
package org.luaj.vm2.lib.jse;

import com.taobao.luaview.util.LogUtil;

import org.luaj.vm2.LuaError;
import org.luaj.vm2.LuaString;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.lib.IoLib;
import org.luaj.vm2.lib.LibFunction;

import java.io.BufferedInputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;

/**
 * Subclass of {@link IoLib} and therefore {@link LibFunction} which implements the lua standard {@code io}
 * library for the JSE platform.
 * <p/>
 * It uses RandomAccessFile to implement seek on files.
 * <p/>
 * Typically, this library is included as part of a call to
 * {@link JsePlatform#standardGlobals()}
 * <pre> {@code
 * Globals globals = JsePlatform.standardGlobals();
 * globals.get("io").get("write").call(LuaValue.valueOf("hello, world\n"));
 * } </pre>
 * <p/>
 * For special cases where the smallest possible footprint is desired,
 * a minimal set of libraries could be loaded
 * directly via {@link Globals#load(LuaValue)} using code such as:
 * <pre> {@code
 * Globals globals = new Globals();
 * globals.load(new JseBaseLib());
 * globals.load(new PackageLib());
 * globals.load(new JseIoLib());
 * globals.get("io").get("write").call(LuaValue.valueOf("hello, world\n"));
 * } </pre>
 * <p>However, other libraries such as <em>MathLib</em> are not loaded in this case.
 * <p/>
 * This has been implemented to match as closely as possible the behavior in the corresponding library in C.
 *
 * @see LibFunction
 * @see JsePlatform
 * @see org.luaj.vm2.lib.jme.JmePlatform
 * @see IoLib
 * @see JmeIoLib
 * @see <a href="http://www.lua.org/manual/5.2/manual.html#6.8">Lua 5.2 I/O Lib Reference</a>
 */
public class JseIoLib extends IoLib {

    protected File wrapStdin() throws IOException {
        return new StdinFile();
    }

    protected File wrapStdout() throws IOException {
        return new StdoutFile(FTYPE_STDOUT);
    }

    protected File wrapStderr() throws IOException {
        return new StdoutFile(FTYPE_STDERR);
    }

    protected File openFile(String filename, boolean readMode, boolean appendMode, boolean updateMode, boolean binaryMode) throws IOException {
        RandomAccessFile f = new RandomAccessFile(filename, readMode ? "r" : "rw");
        if (appendMode) {
            f.seek(f.length());
        } else {
            if (!readMode)
                f.setLength(0);
        }
        return new FileImpl(f);
    }

    protected File openProgram(String prog, String mode) throws IOException {
        final Process p = Runtime.getRuntime().exec(prog);
        return "w".equals(mode) ?
                new FileImpl(p.getOutputStream()) :
                new FileImpl(p.getInputStream());
    }

    protected File tmpFile() throws IOException {
        java.io.File f = java.io.File.createTempFile(".luaj", "bin");
        f.deleteOnExit();
        return new FileImpl(new RandomAccessFile(f, "rw"));
    }

    private static void notimplemented() {
        throw new LuaError("not implemented");
    }


    private final class FileImpl extends File {
        private final RandomAccessFile file;
        private final InputStream is;
        private final OutputStream os;
        private boolean closed = false;
        private boolean nobuffer = false;

        private FileImpl(RandomAccessFile file, InputStream is, OutputStream os) {
            this.file = file;
            this.is = is != null ? is.markSupported() ? is : new BufferedInputStream(is) : null;
            this.os = os;
        }

        private FileImpl(RandomAccessFile f) {
            this(f, null, null);
        }

        private FileImpl(InputStream i) {
            this(null, i, null);
        }

        private FileImpl(OutputStream o) {
            this(null, null, o);
        }

        public String tojstring() {
            return "file (" + this.hashCode() + ")";
        }

        public boolean isstdfile() {
            return file == null;
        }

        public void close() throws IOException {
            closed = true;
            if (file != null) {
                file.close();
            }
        }

        public void flush() throws IOException {
            if (os != null)
                os.flush();
        }

        public void write(LuaString s) throws IOException {
            if (os != null)
                os.write(s.m_bytes, s.m_offset, s.m_length);
            else if (file != null)
                file.write(s.m_bytes, s.m_offset, s.m_length);
            else
                notimplemented();
            if (nobuffer)
                flush();
        }

        public boolean isclosed() {
            return closed;
        }

        public int seek(String option, int pos) throws IOException {
            if (file != null) {
                if ("set".equals(option)) {
                    file.seek(pos);
                } else if ("end".equals(option)) {
                    file.seek(file.length() + pos);
                } else {
                    file.seek(file.getFilePointer() + pos);
                }
                return (int) file.getFilePointer();
            }
            notimplemented();
            return 0;
        }

        public void setvbuf(String mode, int size) {
            nobuffer = "no".equals(mode);
        }

        // get length remaining to read
        public int remaining() throws IOException {
            return file != null ? (int) (file.length() - file.getFilePointer()) : -1;
        }

        // peek ahead one character
        public int peek() throws IOException {
            if (is != null) {
                is.mark(1);
                int c = is.read();
                is.reset();
                return c;
            } else if (file != null) {
                long fp = file.getFilePointer();
                int c = file.read();
                file.seek(fp);
                return c;
            }
            notimplemented();
            return 0;
        }

        // return char if read, -1 if eof, throw IOException on other exception
        public int read() throws IOException {
            if (is != null)
                return is.read();
            else if (file != null) {
                return file.read();
            }
            notimplemented();
            return 0;
        }

        // return number of bytes read if positive, -1 if eof, throws IOException
        public int read(byte[] bytes, int offset, int length) throws IOException {
            if (file != null) {
                return file.read(bytes, offset, length);
            } else if (is != null) {
                return is.read(bytes, offset, length);
            } else {
                notimplemented();
            }
            return length;
        }
    }

    private final class StdoutFile extends File {
        private final int file_type;

        private StdoutFile(int file_type) {
            this.file_type = file_type;
        }

        public String tojstring() {
            return "file (" + this.hashCode() + ")";
        }

		/*private final PrintStream getPrintStream() {
            return file_type == FTYPE_STDERR?
					globals.STDERR:
					globals.STDOUT;
		}*/

        public void write(LuaString string) throws IOException {
//            getPrintStream().write(string.m_bytes, string.m_offset, string.m_length);//使用LogUtil来代替
            if (file_type == FTYPE_STDERR) {
                LogUtil.e(string.tojstring());
            } else {
                LogUtil.i(string.tojstring());
            }
        }

        public void flush() throws IOException {
//            getPrintStream().flush();//使用LogUtil则没必要使用了
        }

        public boolean isstdfile() {
            return true;
        }

        public void close() throws IOException {
            // do not close std files.
        }

        public boolean isclosed() {
            return false;
        }

        public int seek(String option, int bytecount) throws IOException {
            return 0;
        }

        public void setvbuf(String mode, int size) {
        }

        public int remaining() throws IOException {
            return 0;
        }

        public int peek() throws IOException, EOFException {
            return 0;
        }

        public int read() throws IOException, EOFException {
            return 0;
        }

        public int read(byte[] bytes, int offset, int length)
                throws IOException {
            return 0;
        }
    }

    private final class StdinFile extends File {
        private StdinFile() {
        }

        public String tojstring() {
            return "file (" + this.hashCode() + ")";
        }

        public void write(LuaString string) throws IOException {
        }

        public void flush() throws IOException {
        }

        public boolean isstdfile() {
            return true;
        }

        public void close() throws IOException {
            // do not close std files.
        }

        public boolean isclosed() {
            return false;
        }

        public int seek(String option, int bytecount) throws IOException {
            return 0;
        }

        public void setvbuf(String mode, int size) {
        }

        public int remaining() throws IOException {
            return 0;
        }

        public int peek() throws IOException, EOFException {
            globals.STDIN.mark(1);
            int c = globals.STDIN.read();
            globals.STDIN.reset();
            return c;
        }

        public int read() throws IOException, EOFException {
            return globals.STDIN.read();
        }

        public int read(byte[] bytes, int offset, int length)
                throws IOException {
            return globals.STDIN.read(bytes, offset, length);
        }
    }
}
